The World Wide Web includes a network of servers on the Internet, each of which is associated with one or more HTML (Hypertext Markup Language) pages. The HTML pages associated with a server provide information and hypertext links to other documents on that and (usually) other servers. Servers communicate with clients by using the Hypertext Transfer Protocol (HTTP). The servers listen for requests from clients for their HTML, pages, and are therefore often referred to as "listeners."
Users of the World Wide Web use a client program, referred to as a browser, to request, decode and display information from listeners. When the user of a browser selects a link on an HTML page, the browser that is displaying the page sends a request over the Internet to the listener associated with the Universal Resource Locator (URL) specified in the link. In response to the request, the listener transmits the requested information to the browser that issued the request. The browser receives the information, presents the received information to the user, and awaits the next user request.
In some computing environments, a computer user is a "captive audience". For example, the information that is presented to the user of stand-alone software program for the user to get from one program state to another program state is dictated by the program logic of the software in question, and cannot be easily circumvented by the user. Thus, the developer of the stand-alone software can force the user to perform certain actions or view certain information before proceeding to a particular program state.
In contrast, a user of the World Wide Web has virtually unlimited control over the selection of information presented to him or her, and the sequence in which the information is presented. For example, the developer of a particular web site may design a series of web pages that are intended to be viewed in sequence. However, nothing prevents a user from breaking that sequence to view web pages provided at a different site by an entirely different web site developer.
The freedom afforded users of the World Wide Web has encouraged site developers to adopt other ways to encourage users to perform actions or view information that the users would otherwise not choose to do. For example, web site developers frequently encourage web users to view advertisements (which most users would not voluntarily request) by placing attractive links to the advertisements, often in the form of "banners", on web pages that contain information that a user would voluntarily request. The banners may use additional forms of enticement, such as a chance to win a vacation, to encourage the web users to voluntarily request the information they contain.
Even when web site developers invest a significant amount of resources to coax their users to voluntarily perform certain actions, such as view advertisements, they cannot always be sure that all users will voluntarily perform those actions. In some cases, having users perform those actions may be critical to the goal of the site provider. Consequently, it is desirable to provide to web site providers a mechanism for encouraging web users to perform actions or view information that they might not otherwise voluntarily perform when accessing web pages from a web server that has been modified according to the present invention.